"Perl-based approaches to application configuration range from XML or YAML to the Getopt module to Perl code in the configuration file. The downside of these approaches is, of course, that the Perl programmer will pick one of these and disregard the others.
"Instead, programmers should strive to balance the complexity of the code with the needs of the users. Generally speaking, the simplest, most natural configurations are most difficult to support because natural language is simply too organic. Many users, especially Unix users, have been conditioned to believe that certain configuration file formats are 'natural' and easy to learn but in fact those formats, while certainly well-established and terrific in their own right, are arcane to a newcomer..."
